Decreasing spool time with tuning
The fast guys are not retarding timing. Very reliable sources tell me that advancing the timing and leaning it out is the only way to go to get the turbo to spool fast in an auto.
Yeah, you guys are talking about Anti-Lag...it works, very well.
We mainly use it with Autronic, but Haltech, Motec...etc, they all use it.
We are about to tune a DSM - 44ish psi, Anti lag at 8000, flat shift....should be in boost ALL the time!
We mainly use it with Autronic, but Haltech, Motec...etc, they all use it.
We are about to tune a DSM - 44ish psi, Anti lag at 8000, flat shift....should be in boost ALL the time!
Originally Posted by Phil99vette
The fast guys are not retarding timing. Very reliable sources tell me that advancing the timing and leaning it out is the only way to go to get the turbo to spool fast in an auto.
there we go, this is the kind of stuff i was hoping to see. You know this is the first thread in the FI section i have read in about 4 months that i actually learned something about FI?!?!!? crazy. Anyway, my car is up on blocks, but cablebandit i am awaiting any input from your testing tomorrow, this should be interesting. BTW, thanks for putting the effort for a actual scientific test.
So, how lean are we talking here? And how would you activate that in the PCM? just go into PE at 1 point only and give it a lean value, such as 14:1, while giving a high amount of timing such as 35degrees? just throwin out #'s, you guys are on a roll, keep it up.
Gary
So, how lean are we talking here? And how would you activate that in the PCM? just go into PE at 1 point only and give it a lean value, such as 14:1, while giving a high amount of timing such as 35degrees? just throwin out #'s, you guys are on a roll, keep it up.
Gary
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How could the secondary/low timing map/table be activated manually ?[/QUOTE]
it may not be a computer topic-but the new fast computer as 4 outputs for 4 different tunes of cousre which can be activated by a switch-
etc,etc
also the factory pcm in like a gto pontiac has a single output-(i dont know about other ls1
like for me has soon as i hit the n20 switch in the cabin it pulls timming out and runs in the n20 tune until i manually turn off the switch-
so if their is a switch output in the factory pcm-the turbo side of things should be do-able-
it may not be a computer topic-but the new fast computer as 4 outputs for 4 different tunes of cousre which can be activated by a switch-
etc,etc
also the factory pcm in like a gto pontiac has a single output-(i dont know about other ls1
like for me has soon as i hit the n20 switch in the cabin it pulls timming out and runs in the n20 tune until i manually turn off the switch-
so if their is a switch output in the factory pcm-the turbo side of things should be do-able-
Last edited by njc.corp; Sep 19, 2007 at 11:15 PM.
Originally Posted by Grr
there we go, this is the kind of stuff i was hoping to see. You know this is the first thread in the FI section i have read in about 4 months that i actually learned something about FI?!?!!? crazy. Anyway, my car is up on blocks, but cablebandit i am awaiting any input from your testing tomorrow, this should be interesting. BTW, thanks for putting the effort for a actual scientific test.
So, how lean are we talking here? And how would you activate that in the PCM? just go into PE at 1 point only and give it a lean value, such as 14:1, while giving a high amount of timing such as 35degrees? just throwin out #'s, you guys are on a roll, keep it up.
Gary
So, how lean are we talking here? And how would you activate that in the PCM? just go into PE at 1 point only and give it a lean value, such as 14:1, while giving a high amount of timing such as 35degrees? just throwin out #'s, you guys are on a roll, keep it up.
Gary
Originally Posted by stevieturbo
If you could heavily retard the timing on the transbrake, that would fire out past the exhaust valve while it was open, and boost could be almost instant ( anti-lag )
Obviously do this with caution.
If someone could devise a method of using the KR function via a switch, to activate such ign timing....that would be one way to get it to work ?
How could the secondary/low timing map/table be activated manually ?
Obviously do this with caution.
If someone could devise a method of using the KR function via a switch, to activate such ign timing....that would be one way to get it to work ?
How could the secondary/low timing map/table be activated manually ?
No need to play with the KR stuff, rig up the IAT sensor on a normally closed switch, reprogram the ECU to the desired amount of retarded timing in it IAT vs Timing table. Stage, get the engine agains the 2 step, press the switch. Instant timing retard with the stock ecu. You could wire in the whole setup to the clutch switch using a relay. I've tried this method and it works. It does take the ecu about 500mS to recover from the retarded timing though and you gut a huge burst of power when the timing gets added back in.
P.S. this could double as a traction control method using multiple stages of timing retardation while still having the turbo fully spooled.
As for the target a/f. I shoot for 12.5:1 at 5-7psi and have it richen up from there.
Originally Posted by nutz'00 Z28
How lean should one go in order to build boost? My car with the 2 step set at 3400 will build about 5lbs, and at 3900rpm about 14lbs, but it takes way to long setting on the transbrake and creates alot of heat. I have a Yank PY3400 converter, harlan 2-step, th400 w/brake. With it taking so long its impossible to leave hard on the lights, all my reaction times are 4+sec waiting for it to build boost.
Target 12.5:1 a/f upto 7psi and play with the timing. I think i'm around 30 degrees until 1psi and 24ish around 4psi.
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Originally Posted by stevieturbo
If you could heavily retard the timing on the transbrake, that would fire out past the exhaust valve while it was open, and boost could be almost instant ( anti-lag )
Obviously do this with caution.
If someone could devise a method of using the KR function via a switch, to activate such ign timing....that would be one way to get it to work ?
How could the secondary/low timing map/table be activated manually ?
Obviously do this with caution.
If someone could devise a method of using the KR function via a switch, to activate such ign timing....that would be one way to get it to work ?
How could the secondary/low timing map/table be activated manually ?
Originally Posted by Zombie
This will work good for a stick shift car and they way to do it is simple.
No need to play with the KR stuff, rig up the IAT sensor on a normally closed switch, reprogram the ECU to the desired amount of retarded timing in it IAT vs Timing table. Stage, get the engine agains the 2 step, press the switch. Instant timing retard with the stock ecu. You could wire in the whole setup to the clutch switch using a relay. I've tried this method and it works. It does take the ecu about 500mS to recover from the retarded timing though and you gut a huge burst of power when the timing gets added back in.
No need to play with the KR stuff, rig up the IAT sensor on a normally closed switch, reprogram the ECU to the desired amount of retarded timing in it IAT vs Timing table. Stage, get the engine agains the 2 step, press the switch. Instant timing retard with the stock ecu. You could wire in the whole setup to the clutch switch using a relay. I've tried this method and it works. It does take the ecu about 500mS to recover from the retarded timing though and you gut a huge burst of power when the timing gets added back in.
I have built and tested a small device that goes inline with the IAT with nice, clean, factory equiv metri-pack connectors. When armed with 12vdc it replaces the IAT with a fixed value that forces the table to the bottom where it is not used. There is a timing modifier vs. MAP for hte 98-00 models and it is by g/cyl for 01-02s.... 01-02 ALSO have a PE modifier vs. IAT so it could be leaned out or fattened up and then when released you are back at your normal timing and fuel settings. I am actually building 50 up front. It is primarily used for nitrous to pull timing when the N20 is armed ONLY so you can keep peak timing off of the bottle, but I plan to use mine in conjunction with my transbrake to be able to work timing and fueling while on the brake independent from the rest of the tune with a stock PCM. By the time I finish the first batch of these I should be a sponsor here
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From: Norn Iron
No.
The goal of anti-lag, is to maintain boost at all times, when "off" the throttle, so there is zero spool time when depressing the throttle again, but its control strategys can be used for other purposes...eg launch.
Timing will often be ATDC as opposed to BTDC, but it doesnt need a load of fuel. Just enough to make it work.
If using on a closed throttle system ( although I cant see why a drag car would ever need this method ) some form of idle air bypass is required.
For a drag car, your foot will be on the throttle anyway, so no need.
Just pay attention to EGT's !!!
The goal of anti-lag, is to maintain boost at all times, when "off" the throttle, so there is zero spool time when depressing the throttle again, but its control strategys can be used for other purposes...eg launch.
Timing will often be ATDC as opposed to BTDC, but it doesnt need a load of fuel. Just enough to make it work.
If using on a closed throttle system ( although I cant see why a drag car would ever need this method ) some form of idle air bypass is required.
For a drag car, your foot will be on the throttle anyway, so no need.
Just pay attention to EGT's !!!
^werd
Frost, that is probably the smartest and best all around way of doing this. Problem is i dont have a IAT sensor plumbed in yet (oops) so thats for next year. i would guess that it would be quite effective though.
Gary
Frost, that is probably the smartest and best all around way of doing this. Problem is i dont have a IAT sensor plumbed in yet (oops) so thats for next year. i would guess that it would be quite effective though.
Gary
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From: Norn Iron
Who's worried about boost dropping...? not me lol. Its the sissy's who run autos....just plant your right foot and forget...
Nahhh, I prefer to drive my car
Maintaining boost between shifts on a stick/turbo car is easy. Just dont lift your right foot
Nahhh, I prefer to drive my car
Maintaining boost between shifts on a stick/turbo car is easy. Just dont lift your right foot
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Originally Posted by stevieturbo
Who's worried about boost dropping...? not me lol. Its the sissy's who run autos....just plant your right foot and forget...
Nahhh, I prefer to drive my car
Maintaining boost between shifts on a stick/turbo car is easy. Just dont lift your right foot
Nahhh, I prefer to drive my car
Maintaining boost between shifts on a stick/turbo car is easy. Just dont lift your right foot
hahathinking out loud steve, would it be hard to fit a idle bypass valve from something like a cossy to a LS?? what sort of elctonic hardwear would it requier?
if not wuld it still be poss to run anti lag without the vavle??
thanks Chris.
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From: Norn Iron
Anti-lag in its most common form, requires air to enter the engine, as its normal form is when the throttle is closed. But as I say, I see no reason why a drag car would ever need this, as the throttle will always be open.
Using the same fuel/ign strategies for other purposes at all other times, does not require any form of idle air bypass.
Simplest way of doing closed throttle anti-lag is with a simple solenoid valve, or mechanical choke cable linkage to open the throttle a little
Using the same fuel/ign strategies for other purposes at all other times, does not require any form of idle air bypass.
Simplest way of doing closed throttle anti-lag is with a simple solenoid valve, or mechanical choke cable linkage to open the throttle a little
